Recorder/reproducer

ABSTRACT

A recorder/reproducer for recording and reproducing signals includes a receiver which receives signals, a first recorder which records the signals received by the receiver on a first recording medium, and a first reproducer which reproduces the signals recorded on the first recording medium. A second recorder is provided which records the signals reproduced by the first reproducer on a second recording medium, a detector is provided which detects a commercial message portion from the signals recorded on the second recording medium, and a second reproducer is provided which reproduces the signals recorded on the second recording medium while excluding the commercial message portion detected by the detector.

TECHNICAL FIELD

The present invention relates to a recorder/reproducer capable ofsimultaneously making recording/reproduction and other signalprocessings.

The present invention particularly relates to a digitalrecorder/reproducer that can simultaneously and independently makedigital time-base compression/expansion of a video signal, an audiosignal and an information signal and record/reproduce those processedsignals on or from a plurality of recording media.

BACKGROUND ART

In a home recorder/reproducer such as a digital recorder/reproducer (forexample, a digital VTR), video and audio signals are digitized in orderto consume a small amount of tape consumption and to record for a longtime, and they are further coded at a high efficiency to reduce theamount of data.

For example, the now commercialized home digital VTR compresses theamount of video signal to about ⅕ (approximately 25 M bps), and thenrecords the compressed data on a magnetic tape. The video and audiosignals, after being digitized, can be recorded with high quality.

The techniques for recording information of such compressed digitalvideo and audio signals on a magnetic tape or magnetooptical disk aredisclosed in JP-A-9-160753.

In addition, another home VTR that discriminates the commercials from acurrent television broadcast and reproduces them for quick seeing hasbeen manufactured. This VTR is disclosed in, for example, JP-A-5-250762,and further improved in its usability.

DISCLOSURE OF INVENTION

However, in order that the signal recorded in the past is reproduced inthe normal mode and special mode while a real time input signal of avideo signal or the like is being recorded, by use of the home digitalVTR mentioned above or home analog VTR (for example, VHS-VTR, 8-mm VTR),it is necessary to provide a plurality of recording and/or reproducingapparatus.

In the home VTR capable of reproducing the commercials for quick seeing,since the switching points of the commercials were discriminated by theaudio mode, the accuracy at which the commercial switching points werediscriminated was low, and the portions left after cutting off thecommercials could not be reproduced.

It is an object of the invention to provide a recorder/reproducer withthe above problems solved, and in which, when a signal is beingrecorded/reproduced on or from a recording medium such as tape, anothersignal can be recorded/reproduced or processed.

Particularly, it is an object of the invention to provide a digitalrecorder/reproducer capable of recording a video signal, audio signaland information signal, and at the same time reproducing the previouslyrecorded signal in the normal mode and special mode. It is anotherobject of the invention to provide a digital recorder/reproducer capableof actualizing the performance such as the reproduction and recording ofa broadcast signal with the commercials cut off by predicting thebeginning points and closing points of the commercials of the televisionbroadcast at the time of reproduction or recording, and further capableof being improved in its usability.

According to the invention, in order to achieve the above objects, thereis provided a recorder/reproducer having input means through which afirst signal is fed, first recorder/reproducer means for recording thefirst signal on a first recording medium and reproducing the firstsignal from the first recording medium, second recorder/reproducer meansfor recording the first signal reproduced by the firstrecorder/reproducer means on a second recording medium, and reproducingthe first signal from the second recording medium, output means forsupplying the first signal reproduced by the second recorder/reproducermeans, and control means for controlling the processing of the signals,this control means, when the first recorder/reproducer means starts torecord the first signal at a first time and ends to record it at asecond time, controlling the second recorder/reproducer means to delaythe first signal a predetermined time from the second time and to startrecording the first signal from a third time ahead of the second time.Thus, the fed signal can be delayed a certain time, and recorded on therecording medium.

In the recorder/reproducer, signal processor means is further providedfor making a certain process on the second signal during the intervalfrom the first time to the third time. Thus, during the delayed time,other processing can be made.

In the recorder/reproducer, the amount of information the first and/orsecond recorder/reproducer means can record or reproduce per unit timeis made larger than that of the first signal fed to the input means perunit time. Thus, the first and/or second recorder/reproducer means canmake other processing than the processing of the input signal.

In the recorder/reproducer, compressor means is further provided forcompressing the first signal at a predetermined compression ratio orbuffer means is further provided to be connected to the firstrecorder/reproducer means to accumulate signal information until acertain amount of information is accumulated, and then supplying theaccumulated information, and the control means controls the secondrecorder/reproducer means to end recording the first signal at a fourthtime so that a second time interval from the third time to the fourthtime can be reduced relative to a first time interval from the firsttime to the second time. Thus, the time for recording process can bereduced.

In the recorder/reproducer, the control means controls either the firstrecorder/reproducer means or the second recorder/reproducer means torecord or reproduce the first signal at each of a plurality of timesinto which the time interval from the third time to the second time isdivided. Thus, recording and reproduction can be apparentlysimultaneously performed.

In the recorder/reproducer, the second recording medium is a tape-likerecording medium and the first recording medium is a disk-like recordingmedium or semiconductor memory. Thus, the second recording medium canrecord a large amount of information, while the first recording mediumcan be accessed in a short access time.

In the recorder/reproducer, the first recorder/reproducer means makesaccess to a certain amount of signal in a shorter access time than thesecond recorder/reproducer means. Thus, as compared with the secondrecorder/reproducer means, the first recorder/reproducer means can makeprocessing faster. For example, even though the second recording mediumis a tape-like recording medium that takes a long access time, the firstrecorder/reproducer means that can access in a short time can compensatefor this defect, and make useful the advantage of the tape-likerecording medium capable of recording a large amount of information.

In the recorder/reproducer, the second signal is the first signal fed tothe input means as a broadcast program, and the signal processor meansmakes the certain process for discriminating commercials included in thebroadcast program from the program itself. Thus, the commercials can bediscriminated from the program itself during the delayed time.

In the recorder/reproducer, when the first signal fed to the input meansis a compressed signal, the signal processor means expands thecompressed signal, and then discriminates the commercials from theprogram itself. Thus, the commercials in the signal after being expandedto the actual time interval can be discriminated from the programitself.

In the recorder/reproducer, the first signal reproduced from the firstrecorder/reproducer means is a compressed signal, the compressed signalincludes a time stamp signal as time information at every certain times,the signal processor means expands the compressed signal in such amanner as to include the time stamp signal, and specifies thecommercials in association with the time stamp signal, and the controlmeans controls the second recorder/reproducer means to record thecompressed first signal while removing the commercials or addingpositional information of the commercials by use of the results from thesignal processor means that specifies the commercials on the basis ofthe time stamp signal. Thus, the commercials can be removed, and thecommercial information can be added to the compressed data.

In the recorder/reproducer, the signal processor means makes the certainprocess for another signal, as the second signal different from thefirst signal, that the second recorder/reproducer means records orreproduces. Thus, even when the first signal is fed to the input means,another signal can be processed.

In the recorder/reproducer, the broadcast program includes videoinformation and audio information, and the signal processor meansdetects variable points at which the video information and/or audioinformation cause certain changes, and discriminates the commercialsfrom the program itself by use of time intervals in which the changesoccur. Thus, the commercials can be discriminated from the programitself by use of the time intervals in which the changes of video andaudio information occur.

In the recorder/reproducer, the control means controls the secondrecorder/reproducer means to record the first signal while removing thecommercials by use of the results from the signal processor means thatdiscriminates the commercials from the program itself. Thus, the signalwith the commercials removed can be recorded on the recording medium.

In the recorder/reproducer, the control means controls the secondrecorder/reproducer means to record the first signal and information ofthe results from the signal processor means that discriminates thecommercials from the program itself, together on the second recordingmedium. Thus, since the commercial information is recorded on therecording medium, the commercial information can be referred to at thetime of reproduction.

In the recorder/reproducer, when the second recorder/reproducer meansrecords the first signal, the control means controls information of theresult from the signal processor means that discriminates thecommercials from the program itself to be stored in commercialinformation storage means. Thus, the commercial information can beobtained referring to the commercial information storage means.

In the recorder/reproducer, the control means controls said firstrecorder/reproducer means to process at each of a plurality of signalsections into which the signal fed to the input means is divided. Thus,even though the capacity of the first recording medium is small, theinput signal can be processed.

There is also provided a recorder/reproducer for recording andreproducing signals, having third recorder/reproducer means forreproducing a third signal from a third recording medium, fourthrecorder/reproducer means for recording the third signal reproduced bythe third recorder/reproducer means on a fourth recording medium, andreproducing the third signal from the fourth recording medium, outputmeans for supplying the third signal reproduced by the fourthrecorder/reproducer means, and control means for controlling theprocessing of the signals, wherein when the third recorder/reproducermeans starts to reproduce the third signal at a fifth time and ends thereproduction at a sixth time, the control means controls the outputmeans to start supplying the third signal at a seventh time that isdelayed a certain time from the fifth time and ahead of the sixth time.Thus, the time at which data is produced can be delayed relative to thetime at which data is reproduced.

In the recorder/reproducer, signal processor means is further providedfor making a predetermined process on a fourth signal in the timeinterval from the fifth time to the seventh time. Thus, other processingcan be made during the delayed time.

In the recorder/reproducer, the amount of information the fourthrecorder/reproducer means can record or reproduce per unit time islarger than the amount of information of the third signal the thirdrecorder/reproducer means reproduces per unit. Thus, the fourthrecording medium can be recorded and reproduced.

In the recorder/reproducer, the control means controls the fourthrecorder/reproducer means to record the third signal reproduced by thethird recorder/reproducer means and reproduce the recorded fourth signalfrom the fourth recording medium during the interval from the seventhtime to the sixth time.

In the recorder/reproducer, the control means controls the fourthrecorder/reproducer means to record the third signal reproduced by thethird recorder/reproducer means or reproduce the recorded fourth signalfrom the fourth recording medium at each of a plurality of time sectionsinto which the time interval from the seventh time to the sixth time isdivided. Thus, recording and reproduction can be apparentlysimultaneously carried out.

In the recorder/reproducer, the third recording medium is a tape-likerecording medium, and the fourth recording medium is a disk-likerecording medium or semiconductor memory. Thus, a large amount ofinformation can be recorded on the third recording medium, and thefourth recording medium can be accessed in a short access time.

In the recorder/reproducer, the access time in which the fourthrecorder/reproducer means makes access to a certain amount of signal isshorter than the third recorder/reproducer means. Thus, the fourthreorder/reproducer means can make faster processing than the thirdrecorder/reproducer means. For example, even though the third recordingmedium is a tape-like recording medium that takes a long access time,the fourth recorder/reproducer means that makes processing in a shortaccess time can compensate for this defect, and make useful theadvantage of the tape-like recording medium that can record a largeamount of information.

In the recorder/reproducer, the third signal reproduced by the thirdrecorder/reproducer means is a broadcast program, and the signalprocessor means receives the third signal reproduced by the thirdrecorder/reproducer means as the fourth signal, and makes thepredetermined process on the fourth signal so that commercials includedin the broadcast program can be discriminated from the program itself.Thus, the commercials can be discriminated from the program itselfduring the delayed time.

In the recorder/reproducer, when the third signal reproduced by thethird recorder/reproducer means is a compressed signal, the signalprocessor means expands the compressed signal, and then discriminatesthe commercials from the program itself. Thus, the commercials in thesignal after being expanded to the actual time intervals can bediscriminated from the program itself.

In the recorder/reproducer, the third signal reproduced by the thirdrecorder/reproducer means is a compressed signal including a time stampsignal as time information at every predetermined times, the signalprocessor means expands the compressed signal in such a manner as toinclude the time stamp signal, and specifies the commercials accordingto the time stamp signal, and the control means controls the fourthrecorder/reproducer means to reproduce the third compressed signal whileexcluding the commercials by use of the results from the signalprocessor means that discriminates the commercials from the programitself on the basis of the time stamp signal. Thus, the commercials canbe removed, and the commercial information can be added to thecompressed data.

In the recorder/reproducer, the broadcast program includes videoinformation and audio information, and the signal processor meansdetects variable points at which the video information and/or the audioinformation cause certain changes, and discriminates the commercialsfrom the program itself by use of time intervals in which the changesoccur. Thus, the commercials can be discriminated from the programitself by use of the time intervals in which the changes of video andaudio information occur.

In the recorder/reproducer, the control means controls the fourthrecorder/reproducer means to reproduce the third signal while removingthe commercials by use of the results from the signal processor meansthat discriminates the commercials from the program itself. Thus, thesignal with the commercials removed can be recorded on the recordingmedium.

In the recorder/reproducer, the control means controls said fourthrecorder/reproducer means at each of a plurality of signal sections intowhich the third signal reproduced by the third recorder/reproducer meansis divided. Thus, even though the capacity of the fourth recordingmedium is small, the signal can be processed.

There is also provided a digital recorder/reproducer having a fifthrecording medium and a sixth recording medium on and from which an inputsignal including at least a video signal is recorded and reproduced, andcapable of transmitting input and output signals between the recordingmedia, characterized in that the digital recorder/reproducer reproducesthe sixth recording medium while recording the input signal on the fifthrecording medium.

There is also provided a digital recorder/reproducer having a fifthrecording medium and a sixth recording medium on and from which an inputsignal including at least a video signal is recorded and reproduced, andcapable of transmitting input and output signals between the recordingmedia, characterized in that while the digital recorder/reproducer isrecording the input signal on the sixth recording medium at a firstrecording position, the digital recorder/reproducer records a signalreproduced from a first position of the fifth recording medium on thesixth recording medium at a second recording position, and while thedigital recorder/reproducer is reproducing the input signal recorded atthe first recording position of the sixth recording medium and recordingthe reproduced signal on the fifth recording medium at a secondrecording position, the digital recorder/reproducer reproduces therecorded signal from the second recording position of the fifthrecording medium. Thus, recording and reproduction can be apparentlysimultaneously performed by the recorder/reproducer.

In the digital recorder/reproducer, the speed of an input/output signalrecorded/reproduced on and from said fifth recording medium is differentfrom that recorded/reproduced on and from said sixth recording medium.Thus, the above operation can be performed when input and output signalsare supplied at different speeds.

There is also provided a digital recorder/reproducer having fifthrecorder/reproducer means and sixth recorder/reproducer means forrecording and reproducing signals on a fifth recording medium and asixth recording medium and capable of transmitting input and outputsignals between the recording media, the digital recorder/reproducerhaving receiver means for receiving a video signal, an audio signal andan information signal, compressed data generator means for compressingthe video and audio signals to produce compressed data, expanded datagenerator means for expanding the compressed data to produce theoriginal video and audio signals, recorder/reproducer means forrecording and reproducing the compressed data on and from the fifthrecording medium and the sixth recording medium, and data selector meansfor selectively switching signals reproduced from the fifth recordingmedium and the sixth recording medium, and the compressed data from thecompressed data generator means, whereby while the compressed data isbeing recorded on the fifth recording medium, the sixth recording mediumis reproduced. Thus, the compressed data can be processed.

In the digital recorder/reproducer, there are further provided CMpredictor means for predicting the start and end points of commercialsincluded in a television broadcast, CM history memory means for storingthe CM predicted results, and first control means for changing theplaces for signals to be recorded and reproduced, of the fifth and sixthrecording media in accordance with the CM history information. Thus, thesignal with the commercials removed can be reproduced.

In the digital recorder/reproducer, there are further providedmulti-receiver means for receiving a plurality of television broadcastsat a time, multi-compressed-data generator means for compressing each ofthe signals received by the multi-receiver means, and multi-recordermeans for recording each of the compressed data obtained from themulti-compressed-data generator means on the fifth and sixth recordingmedia. Thus, a plurality of television broadcasts can be recorded.

In the digital recorder/reproducer, the digital compressed datagenerator means has compression-ratio changing means for changing thecompression ratio adaptively according to the video signal and/or theaudio signal, and after a certain amount of data is recorded on saidfifth recording medium, the compressed data are transmitted from thefifth recording medium to the sixth recording medium, and recordedthereon. Thus, data of small amounts can be effectively processed.

In the digital recorder/reproducer, transmission speed detector means isfurther provided for detecting that the compressed data is generatedfrom the compressed data generator means at a transmission speeddifferent from that of the compressed data recorded on the fifthrecording medium, and after the compressed data of a certain amount isrecorded on the sixth recording medium, the compressed data istransmitted from the second recording medium to the fifth recordingmedium, and recorded thereon on the basis of the detected results. Thus,data can be effectively recorded on the recording medium.

In the digital recorder/reproducer, means is further provided forreproducing the fifth recording medium and at the same time transmittingthe compressed data reproduced from the fifth recording medium to thesixth recording medium, thus recorded thereon, and when the past videoand audio signals are reproduced from the fifth recording medium, thesignals are reproduced from the sixth recording medium. Thus, recordingand reproduction can be made effectively.

In the digital recorder/reproducer, there are further provided time codegenerator means for generating time information (time code signal), timecode recorder/reproducer means for recording and reproducing the timecode signal on and from the fifth and sixth recording media, controlmeans for controlling the reproduction positions of the fifth and sixthrecording media from which data is reproduced, in accordance with thetime code signal, and the data selector means is operated to switch inaccordance with the reproduced time code signal. Thus, the timeinformation can be managed.

In the digital recorder/reproducer, there are further provided means forrecording the video signal, audio signal and information signal(television broadcast) from the receiver means on the fifth recordingmedium, means for recording a certain portion of the televisionbroadcast program on the sixth recording medium, means for making thefifth recording medium be ready for reproduction while reproducing thesixth recording medium, and control means for controlling thereproduction positions of the fifth and sixth recording media from whichdata is reproduced, in accordance with the reproduced time code signal,and the data selector means is operated to switch the reproduced signalsfrom the fifth and sixth recording media in accordance with the timecode signal. Thus, effectively the reproduction positions can becontrolled and the recording and reproduction can be made.

In the digital recorder/reproducer, simultaneous recorder/reproducermeans is further provided for recording on the sixth recording mediumand at the same time reproducing the sixth recording medium from anarbitrary position. Thus, recording and reproduction can besimultaneously made on and from the sixth recording medium.

In the digital recorder/reproducer, the fifth recording medium is amagnetic tape, magnetic disk, magnetooptical disk, phase change opticaldisk or semiconductor memory, and the sixth recording medium is amagnetic tape, magnetic disk, magnetooptical disk, phase change opticaldisk or semiconductor memory. Thus, the above operation can be made byuse of a plurality of recording media of different kinds.

In the digital recorder/reproducer, the recording capacity of the fifthrecording medium is different from that of the sixth recording medium.Thus, the above operation can be made on the recording media ofdifferent capacities.

In the digital recorder/reproducer, the compressed data generator meansand expanded data generator means are based on MPEG system. Thus, datacan be compressed and expanded according to the MPEG system.

In the digital recorder/reproducer, the compressed data generator meansand expanded data generator means can arbitrarily change the compressionratio and expansion ratio. Thus, data processing can be made moreeffectively.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram of the construction of a digitalrecorder/reproducer according to the first embodiment of the invention.

FIG. 2 is a diagram showing the state in which the HDD and magnetic tapeare operated.

FIG. 3 is a digram to which reference is made in explaining the state inwhich data is transferred in the first embodiment of the invention.

FIG. 4 is a diagram showing the results of calculating the HDD buffercapacity.

FIG. 5 is a block diagram of the construction of a digitalrecorder/reproducer according to the second embodiment of the invention.

FIG. 6 is a digram showing the CM cutting operation.

FIG. 7 is a block diagram of the construction of a digitalrecorder/reproducer according to the fifth embodiment of the invention.

FIG. 8 is a diagram to which reference is made in explaining the statein which data is transferred in a modification of the fifth embodimentof the invention.

FIG. 9 is a block diagram of the construction of a digitalrecorder/reproducer according to the sixth embodiment of the invention.

FIG. 10 is a block diagram of the construction of a digitalrecorder/reproducer according to the third embodiment of the invention.

FIGS. 11 and 12 are imaging diagrams for explaining the removal of CM.

FIG. 13 is a block diagram of the construction of a digitalrecorder/reproducer according to the fourth embodiment of the invention.

FIG. 14 is a block diagram of the construction of a digitalrecorder/reproducer according to the second embodiment of the invention.

FIG. 15 is a block diagram of the construction of a digitalrecorder/reproducer to the third embodiment of the invention.

FIG. 16 is a block diagram of the construction of a digitalrecorder/reproducer to the third embodiment of the invention.

FIG. 17 is a block diagram of the construction of a digitalrecorder/reproducer according to the second embodiment of the invention.

FIG. 18 is a diagram to which reference is made in explaining the statein which a digital signal is transferred at the time of reproduction.

FIG. 19 is a block diagram of the construction of a digitalrecorder/reproducer according to the second embodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The constructions of embodiments of a digital recorder/reproducer of theinvention and the processing of the video and audio signals will bedescribed in detail with reference to the drawings.

In the following descriptions about the operation of digitalrecorder/reproducer, the first and second recording media are assumed asmagnetic tape and hard disk (hereinafter, HDD). In the embodiments ofthe invention, the first recording medium may be a magnetic disk,magnetooptical disk, phase change optical disk or semiconductor memory.Similarly, the second recording medium may be a magnetic disk,magnetooptical disk, phase change optical disk or semiconductor memory.

First Embodiment

The construction of a digital recorder/reproducer according to the firstembodiment of the invention, and the signal processing will be describedwith reference to FIG. 1. FIG. 1 is a block diagram of the constructionof a digital recorder/reproducer according to the first embodiment.

A digital recorder/reproducer 1 is formed of a reception/compressionprocessor 3 that receives an analog television broadcast, converts thereceived signal into a digital signal, compresses the digital data andsupplies the digital compressed data, a recording/reproducing processor5 for recording and reproducing the digital compressed data, anexpansion/reproduction processor 7 for expanding the digital compresseddata and converting it back to the analog signal, and a control unit 9for controlling the transfer of digital compressed data between thoseprocessors and the recording/reproducing processor 5.

The reception/compression processor 3 includes an analog receiver 31, aVBI decoder 32, a video analog-digital converter (hereinafter, videoADC) 33, an audio analog-digital converter (hereinafter, audio ADC) 34,a video decoder 35, and a data compressor 36.

The recording/reproducing processor 5 includes a digital VTRrecorder/reproducer 51 as the first recorder/reproducer means, a harddisk recorder/reproducer 52 as the second recorder/reproducer means, afirst digital recording processor 53 for executing the processing of asignal to be recorded in the first recorder/reproducer, a first digitalreproducing processor 54 for executing the processing of the signalreproduced from the first recorder/reproducer, a second digitalrecording processor 55 for executing the processing of a signal to berecorded in the second recorder/reproducer, and a second digitalreproducing processor 56 for executing the processing of the signalreproduced from the second recorder/reproducer. Therecording/reproducing processor 5 further includes three switchingcircuits 57, 58, 59 for switching the paths of the digital signals.

The expansion/reproduction processor 7 includes a data expander 71, avideo encoder 72, an audio digital-analog converter (hereinafter, audioDAC) 73, and a video digital-analog converter (hereinafter, video DAC)74.

The control unit 9 includes a controller 91 formed of a microcomputer, adisplay panel 92, and an operation panel 93.

The analog receiver 31 of the reception/compression processor 3selectively receives a desired channel of the analog televisionbroadcasts received by an antenna 10, and produces an analog videosignal and an analog audio signal.

The VBI decoder 32 decodes the information signal multiplexed in thevertical blanking periods of the video signal. This information signalincludes, for example, text information, caption information and newsinformation.

The video ADC 33 converts the analog video signal to a digital videosignal.

The audio ADC 34 converts the analog audio signal to a digital audiosignal.

The video decoder 35 converts the digital video signal to digital databased on ITU-R BT. 601 (International Telecommunication Union, RadioCommunication Center).

The data compressor 36, for example, encodes the digital video signal ata high efficiency according to MPEG 2 (Moving Picture Experts Group 2)to generate video digital compressed data, and superimposes the audiodigital signal and decoded information signal on the video digitalcompressed data.

This video digital compressed data is transmitted via the E contact ofthe switching circuit 57 to the digital recording processor 53, directlyto the digital recording processor 55, and via the contact EE of theswitching circuit 59 to the data expander 71.

A digital recorder/reproducer (hereinafter, digital VTR) was used as thefirst recorder/reproducer means 51 of the recording/reproducingprocessor 5, and a hard disk recorder/reproducer (hereinafter, HDD unit)as the second recorder/reproducer means 52.

The digital recording processors 53, 55 have substantially the samefunction. The digital recording processors 53, 55 each include a buffer,an encoding circuit for error correction code, a framing circuit, and achannel modulating circuit, thereby encoding the video digitalcompressed data to make error correction code, and framing andchannel-modulating it.

To the digital recording processor 53 are supplied the video digitalcompressed data from the data compressor 36 via the E contact of theswitching circuit 57, and the video digital compressed data from thedigital reproducing processor 56 via the F contact thereof.

The output signal from the digital recording processor 53 is supplied tothe digital VTR 51, and recorded on a magnetic tape. Here, in additionto the video digital compressed data, the above-mentioned informationsignal and a time code signal generated within the controller 91 arerecorded on the magnetic tape.

Similarly, to the digital recording processor 55 are supplied the videodigital compressed data directly from the data compressor 36, and thevideo digital compressed data from the digital reproducing processor 54via the B contact of the switching circuit 58.

The output signal from the digital recording processor 55 is supplied tothe HDD unit 52, and recorded on the hard disks. On the HDD are recordedthe information signal and time code signal generated within thecontroller 91 in addition to the video digital compression data as inthe digital VTR 51.

The digital reproducing processors 54, 56 have substantially the samefunction. The digital reproducing processor 54, 56 each have a channeldemodulating circuit, a decode circuit for error correction code, and aframe decomposition circuit, thereby making channel demodulation,decoding for error correction code, and frame decomposition on thereproduced signal.

The output from the digital reproducing processor 54 is supplied via theA contact of the switching circuit 58 to the Tape contact of theswitching circuit 59, and via the B contact to the digital recordingprocessor 55.

The output from the digital reproducing processor 56 is supplied via theF contact of the switching circuit 57 to the digital recording processor53, and to the HDD contact of the switching circuit 59.

The data expander 71 of the expansion/reproduction processor 7 expandsthe video digital compressed data sent from the data compressor 36,digital reproducing processor 54 or digital reproducing processor 56into digital video data and digital audio data based on ITU-R BT. 601(International Telecommunication Union, Radio Communication Center)according to an expansion process of, for example, MPEG 2, and suppliesthem to the video encoder 72 and audio DAC 73, respectively.

The video encoder 72 converts the expanded digital video data to thedigital video signal and supplies it to the video DAC 74.

The video DAC 74 converts the digital video signal to the analog videosignal, and supplies it to a video output terminal 76.

The audio DAC 73 converts the expanded digital audio data to the analogaudio signal, and supplies it to an audio output terminal 75.

The controller 91 controls the switching circuits 57, 58, 59 to operate,and controls the drive systems of the digital VTR 51 and HDD unit 52.The controller 91 is connected to the operation panel 93 and displaypanel 92.

According to the digital recorder/reproducer of this embodiment, while abroadcast program is being recorded on the digital VTR 51, thepreviously recorded program can be reproduced and viewed from thedigital VTR 51. This operation will be described with reference to FIGS.2 and 3.

FIG. 2 shows the relation between a recorded program region 511 a and anon-recorded region (a region being recorded) 511 b of a roll ofmagnetic tape 511 set on the digital VTR 51.

FIG. 3 is a diagram showing the transfer of data in this embodiment.

Here, the access time Ta is the maximum time necessary to fast forwardthe tape from the current reproduction position to the beginning end ofthe non-recorded region (or to bring the tape to the recording position)or the maximum time necessary to rewind the tape from the currentrecording position to the reproduction resuming position (or to bringthe tape to the reproduction position). This maximum time is assumed 90seconds in this example.

In addition, it is assumed that the video/audio compression data rate islower than the record/reproduction data rate of the magnetic tape. Inother words, it is assumed that the video/audio compression data rate inthe data compressor 36 of the reception/compression processor (TVreceiver) 3, and the video/audio expansion data rate in the dataexpander 71 of the expansion/reproduction processor 7 are respectively 4Mbps, and that the recording/reproduction data rate of the magnetic tape511 and HDD unit 52 is 12 Mbps.

The operations in which a program is recorded in the non-recorded region511 b and at the same time the previously recorded program is reproducedfrom the recorded program region 511 a of the magnetic tape 511 are theapparent parallel processing of the recording signal and recorded signalthat can be achieved by using the large-capacity HDD unit 52 as abuffer. The HDD unit 52 makes recording and reproduction operations in atime-sharing manner. This means that a predetermine time is divided intoa plurality of intervals of time which are assigned to the recordingoperation and the reproduction operation. The above parallel processingof recording and reproduction operations is emulated by using buffermemories incorporated in the digital recording processor 55 and digitalreproduction processor 56. Even in the following embodiments, the HDDunit 52 makes the same operation. The HDD unit 52 is capable of fasteraccess than the magnetic tape, and thus enough for the buffers.

While the HDD unit 52 is used in this embodiment, the HDD unit 52 may bereplaced by other recording media suitable for random access, such asdisk-like recording media of optical disk and magnetooptical disk orsemiconductor memory.

Here, the maximum tape positioning time, namely, the time necessary tofast forward the tape from the current recorded-region reproducingposition to the beginning end of the non-recorded region, or the timenecessary to rewind the tape from the current recording position to theprogram reproduction position is assumed to be, for example, 90 seconds.Here, for the sake of better understanding, the recording/reproductiondata rate of the magnetic tape is assumed as 12 Mbps, and thevideo/audio compression data rate as 4 Mbps.

First, to reproduce the magnetic tape, the tape is brought to theposition from which the reproduction is to start. It is enough to take90 seconds, maximum for the tape transport. During the time in which themagnetic tape is transported to the reproduction start position, thedigital compressed data (here, recording data) generated on the basis ofthe video and audio signals from the television receiver 3 is recordedon the HDD unit 52. This recording can be made at a data rate of 4 Mbps,minimum.

Then, the switching circuit 58 is switched to the contact B, and apredetermined amount (270 Mbytes) of data (here, called reproduced data)resulting from reproducing the magnetic tape for a certain time (forexample, three minutes) is transferred via this contact to the HDD unit52 where it is recorded. This transfer, if made at a data rate of 12Mbps, minimum, can be completed in three minutes.

At this time, the digital compressed data generated on the basis of thevideo and audio signals from the television receiver 3 is still recordedin the HDD unit 52 in parallel with the reproduction operation.

Moreover, the data recorded in the HDD unit 52 is read and transferredto the data expander so that the reproduced video and audio signals canbe viewed and listened to. This transfer can be made at a data rate of 4Mbps, minimum.

When the recording of a predetermined amount (270 Mbytes) of reproduceddata from the magnetic tape 511 to the HDD unit 52 is finished, themagnetic tape 511 is brought to a certain position within thenon-recorded region 511 b.

Even during this operation, the operations of recording the recordingdata in the HDD unit 52 and reading the reproduced data from the HDDunit 52 are still performed in parallel.

Then, the switching circuit 59 is switched to the HDD contact, and theswitching circuit 57 to the F contact, allowing the recording data to betransferred from the HDD unit 52 to the non-recorded region 511 b of themagnetic tape 511, thus copying the amount of data (270 Mbytes).

Thus, if data is transferred at a high data rate to the magnetic tape,the time taken to transfer is short, and hence the remaining time can beused for other processing.

In parallel with this copy operation, the data stored in the HDD unit 52is read and processed so that it can be viewed and listened to, and therecording data from the television receiver 3 is recorded in the HDDunit 52.

In these processings, the HDD unit 52 apparently simultaneously makesrecording and reproducing operations, and in this case the recording andreproduction of the digital compressed data are alternately repeatedwith a short period of time. In addition, a plurality of heads may beprovided on the HDD unit 52.

Thus, use of a single digital recorder/reproducer according thisembodiment of the invention can achieve the performance of bothrecording the television signal and reproducing the recorded programapparently at the same time by repeating a sequence of these operations.

If this sequence of operations is repeated with a short period of time,the capacity of the HDD unit to be used can be reduced.

With reference to FIG. 4, a description will be made of the use of theHDD unit as a buffer on the basis of the results of computing thevideo/audio compressed data rate and capacity of HDD unit 52.

FIG. 4 shows the relation between the video/audio compressed data rate(Mbps) on the abscissa and the capacity (Mbytes) of HDD unit 52 on theordinate that is necessary as a buffer. Under the above conditions, thecapacity of HDD unit 52 required as a buffer will be found about 270Mbytes and to be small enough to produce at low cost from the graph.

Moreover, the beginning end of a recorded program on the magnetic tape511 can be apparently instantly brought to be ready to start reproducingby a digital recorder/reproducer of the same function blocks having aserial-access large-capacity recorder/reproducer (VTR) and a fastrandom-access recorder/reproducer (HDD).

In this operation, a television program of the same contents is recordedon the magnetic tape 511 and HDD unit 52. At this time, on the HDD unit52, is recorded only the data that continues a predetermine period fromthe beginning end of the program.

In the reproduction operation, the digital compressed data of the aboveprogram is instantly reproduced from the HDD unit 52. During thisoperation, the magnetic tape 511 is fast transported to reach thebeginning end of this program. In this case, the beginning end of thisprogram is positioned a certain time after the currently reproducingposition of the HDD unit 52.

After the end of this positioning, the magnetic tape 511 is started toreproduce, while being adjusted in its transport speed so that the timebases of the digital compressed data currently reproduced from the HDDunit 52 and magnetic tape 511 can be synchronized with each other(hereinafter, called the phase adjusting operation). When the phaseadjusting operation is completed, the switching circuit 59 is switchedfrom the contact HDD to contact Tape, so that switching is made from thereproduction of HDD unit 52 to the reproduction of magnetic tape 511.Thereafter, the digital compressed data reproduced from the magnetictape 511 can be processed and viewed.

The above phase adjusting operation can be made by shifting thereproduced position of the magnetic tape 511 on the basis of the timecodes recorded on the HDD unit 52 and magnetic tape 511 so that bothtime codes can coincide.

Moreover, by using a digital recorder/reproducer of the same functionblocks as the digital recorder/reproducer of this embodiment, it ispossible that, while the program is being recorded, this currentlyrecorded program can be reproduced from the first.

This function is requisite for the user. For example, even when the userpreviously sets a timer of this recorder for a program of 9:00 p.m. to9:54 p.m. so that the program can be started to record during thatperiod of time, and then comes home at 9:20 p.m., the user can view thisprogram from the first (9:00 p.m.) without resetting the timer. Thisoperation will be described with reference to FIGS. 1 and 2.

The user can register the channels, start times and end times of desiredprograms by use of the operation panel 93 and display panel 92.

When a time to record comes, the digital VTR 51 starts recording thedigital compressed data of the video and audio signals of thecorresponding program on the magnetic tape 511.

At the same time, the HDD unit 52 records the same digital compresseddata as above.

At this time, the switching circuit 57 is switched to the contact Eposition, the switching circuit 57 to the contact A position, and theswitching circuit 59 to the contact HDD position.

When the program is viewed from the first while being recorded, thedigital compressed data is reproduced from the HDD unit 52 and decodedso that the original video and audio signals can be reproduced. Evenduring the reproduction of the digital compressed data from the HDD unit52, the digital VTR 51 still continues to record this program.

When the time code of the compressed data reproduced from the HDD unit52 is equal to or larger than that of the digital compressed data thatis being currently recorded in the digital VTR 51, the switching circuit59 is operated to change to the contact EE position, thus bringing aboutthe state in which the user can view in real time the currently on-airprogram.

Therefore, the user can view freely, the programs recorded before thisprogram, in different playback modes such as past playback,speed-changed playback and retry playback.

Thus, according to the first embodiment of the invention, while atelevision signal is being recorded on the recording medium of thedigital recorder/reproducer, the recorded program can be reproduced fromthe same recording medium at the same time.

Moreover, the beginning end of the recorded program on the magnetic tape511 can be apparently instantly drawn out. In addition, while a programis being recorded, the already recorded portion of the program that isbeing currently recorded can be reproduced from an arbitrary position.

While the compression and expansion means in the first embodiment is ofMPEG 2, other type of compression means may be used.

Second Embodiment

A digital recorder/reproducer of the second embodiment of the inventionwill be described below.

In the second embodiment of the invention, a television broadcastprogram and commercials (hereinafter, CM) interposed in the program arediscriminated at the time of recording or reproduction, and only the CMis removed from the program (that is, it is apparently instantly cutoff, reproduced for quick seeing or fast forwarded) so that the user canview substantially only the program itself.

First, the method of discriminating the program and CM will bedescribed. There are now various different methods of discriminatingprogram and CM. Here, a method of discriminating by audio mode andanother method of discriminating from video and audio signals will begiven as examples. The program/CM discrimination means is not limited tothe above, but may be other types.

In the audio-mode discrimination system, the program and CM arediscriminated by whether the audio signal of the received televisionsignal is bilingual, monaural or stereo. In most cases, the televisionbroadcasts have monaural or bilingual audio signal, and CM has stereoaudio signal. Therefore, the stereo mode of the audio signalscorresponds to most of CM. However, in recent television broadcasts, thenumber of the stereo-sound programs is increased, and as a result theaccuracy of discriminating CM from program by the above method isdecreased.

Thus, the audio mode discrimination method is not used, and anothermeans can be instead used for discriminating CM by using audio signal,video signal and time management means.

There are surely silent pauses of 100 m sec or more before and after CM,and the video signal is sure to suddenly change its level because ofscene change when CM starts and ends.

Therefore, it can be considered that the start and end points of CMperiods are detected from both the silent pauses and the sudden levelchange of video signal.

However, there is the possibility that the same silent pause and suddenvideo level change occur in the program, and thus use of only thisdiscrimination method will cause error.

Thus, it can be considered that time condition is added to the method ofdiscriminating by detecting the changes at the start and end points ofCM, thereby more accurately discriminating the program and CM. In otherwords, the CM inserted in the program is often composed of a pluralityof CMs the duration of which is controlled to be a predetermined time(for example, a multiple of 15 seconds).

Therefore, if the changes at the start points or end points of CM aredetected at certain intervals of time (for example, 15 seconds orintegral multiples of that value) or continuously for a certain time orabove, those intervals can be decided to be CM.

The CM decided by the above method is removed (cut off, reproduced forquick seeing, or fast forwarded) from the program by the followingreproducing method.

FIGS. 11 and 12 are imaging diagrams for the CM-removed reproduction. Asillustrated in FIG. 11, the tape has recorded thereon programs A, B andC, four CMs between programs A and B, and two CMs between programs B andC. The HDD unit skips over the CMs and reads the programs, which arethen recorded on the magnetic tape. When the magnetic tape isreproduced, it has no CMs recorded, and thus only the programs A, B andC are continuously reproduced (FIG. 11). Alternatively, the programs andthe CMs are all recorded on the magnetic tape, and at the time ofreproduction the HDD unit buffers those data, and instantly removes (cutoff, reproduces for quick seeing, fast forwards) the CMs on the basis ofthe CM information decided by the above method (see FIG. 12), therebythe programs A, B and C being reproduced as if they were continuous. Oronly the CMs may be fast reproduced.

Examples of the digital recorder/reproducer using the above CMdiscrimination method will be described. First, a first example will bementioned with reference to FIGS. 5 and 6. FIG. 5 is a block diagram ofthe construction of a digital recorder/reproducer according to thesecond embodiment. In FIG. 5, like elements corresponding to those inthe first embodiment are identified by the same reference numerals, andwill not described in detail. FIG. 6 is a diagram to which reference ismade in explaining the construction and operation of the CM cuttingfunction.

The digital recorder/reproducer 1 of this example is different from therecorder/reproducer of the first embodiment in that a CM perioddiscriminating function is added to decide whether the content of thereceived broadcast is currently a program or CM, that single digitalreproduction processor means 56 is used common to the two digitalreproduction processor means 54, 56 of the recording/reproductionprocessor 5, and that another switching circuit 60 is provided forselecting the signal to the digital reproduction processor 56.

CM period discriminating means 8 for achieving the above CM perioddiscriminating function has CM predicting means 81, time managementmeans 82, and a CM history memory 83.

As illustrated in FIG. 6, the CM predicting means 81 includes interfieldscene change detecting means 811, a silent pause detector 812, a CMdiscriminator 813 and a CM interval detector 814.

The interfield scene change detecting means 811 monitors the videosignal, detects the video signal level difference between the fields(for example, luminance signal level difference). When the means 811detects a video signal level change that is equal to or larger than apredetermined value, it decides that it is a scene change, and producesa scene change decision signal.

The silent pause detector 812, when detects a silent pause interval of acertain period or more, generates a silent pause period detectionsignal.

The CM discriminator 813, when detecting both the scene change decisionsignal and the silent pause period detection signal, generates a signalindicating the start point or end point of CM.

The CM interval detector 814 monitors the broadcast time interval (forexample, an interval of 15 seconds) of the signal indicating the startpoint or end point of CM produced from the CM discriminator, and decidesthat the output signal is the signal of having detected the start pointor end point of CM when the time interval of the signal satisfies thebroadcast time interval and a sequence of a plurality of thoseintervals.

The CM predicting mean 81 receives the video signal and audio signal fedfrom the TV receiver 3 and the time information supplied from the timemanager 82, and predicts the start point and end point of CM accordingthe received signals.

The predicted CM start point and end point information is recorded inthe CM history memory 83 to be associated with the time signal recordedon the magnetic tape.

The program recording operation for apparently cutting off the CM willbe described with reference to FIG. 6.

Referring to FIG. 6, the video signal and audio signal fed from thetelevision receiver 3 are supplied through an input terminal to the CMpredicting means. For the sake of easy explanation, a single inputterminal is shown in FIG. 6.

A switching controller 84 operates on the basis of the time-basisrelation between the program and CM stored in the CM history memory 83,or on the recording data recorded on the magnetic tape 511 shown in FIG.6 and the time table indicating the position on the table. The timetable describes the time-basis relation between the program and CMrecorded on the magnetic tape 511.

The magnetic tape 511 has all received contents (recording data), orprogram A, CM, program B, CM and program C recorded in turn from thebeginning end of the tape.

The HDD unit 52 records the recording data according to the time tableas does the magnetic tape 511.

The HDD unit 52, when the CM predicting means 81 detects the start pointand end point of CM, completes the recording of the CM intervalsdescribed on the time table and predetermined periods (Tb) before andafter the CM periods (hereinafter, HDD buffer recording) with the otherportions not recorded, and then continues to record the recording data.

The Tb period has a time set to correspond to the period in which the CMrecorded regions on the magnetic tape are fast forwarded. This set timeis changed adaptively to the CM recorded regions on the magnetic tape.

The HDD buffer recording A period and HDD buffer recording B period ofthe time table are completely recorded in the HDD unit 52.

The HDD unit 52 employs the HDD recording region with the above periodnot completely recorded (imperfect recording region) as a cache region,and repeats the recording in that region.

The method of reproducing the magnetic tape with the CM apparently cutoff will be described with reference to FIG. 6. The time table in FIG. 6is this time replaced by the magnetic tape.

First, the magnetic tape 511 is brought to the beginning end, and theprogram A is reproduced from the tape. When the HDD buffer recording Abegins to be reproduced from the magnetic tape, the switching circuit 60is operated to change from contact PL position to the contact BFposition, and the reproduced HDD buffer recording A is supplied from theHDD unit 52 instead of the magnetic tape 511.

The HDD unit 52 reproduces the Tb regions before and after the HDDbuffer recording A with the CM recorded region jumped over. The HDD unit52 can make the above operation because of its fast random accessingability.

During the period in which the HDD unit 52 is reproducing the HDD bufferrecording A (reproducing 2 Tb periods), the digital VTR 51 fast forwardsthe magnetic tape 511 to bring it to the beginning end of the program B(Ta ahead of the beginning end of the program B), and waits for the HDDunit 53 to end the reproduction of the HDD buffer recording A.

When the HDD buffer recording A is completely reproduced, the reproducedsignal of program B from the magnetic tape is switched to.

Thus, since only the CM periods can be removed, the user can view theprograms A, B and C with the CM apparently cut off.

The reproduced-signals switching operation can be executed by theswitching circuit 60 and the switching controller 84.

While in the above method the data predicted as CM, for example, the HDDbuffer recording A and HDD buffer recording B are recorded in the HDD,and the reproduced signals from the magnetic tape and the HDD areswitched and supplied, a construction using another method may be used.For example, it is assumed that data is read from the HDD 52 in realtime, and that the rate at which the data is read from the VTR 51 isselected to be faster than the real-time reading speed. The data readfrom the VTR 51 is once recorded in the HDD 52. The data previously readfrom the VTR 51 are at least sequentially accumulated for apredetermined time in the HDD 52.

The data accumulated in the HDD 52 are controlled to be sequentiallyreproduced in real time, and the predicted CMs can be cut off bychanging the reading positions in the HDD 52. In addition, if thepredicted CMs reading speed is set to be high, the CMs can be fastreproduced.

In the above example, the CMs are cut off by the HDD unit 52 that refersto the CM history memory 83 in which the CM information decided at thetime of recording is already recorded. Since the CMs can be apparentlycut off or fast reproduced, the user can view the programs continuously,and thus the usability is excellent.

A second example of the digital recorder/reproducer using the above CMdiscrimination method will be described. In the first example the CMsare cut off, reproduced for quick seeing or fast forwarded on the basisof the program and CM history information recorded in the CM historymemory when the program is recorded, while in the second example theprogram and CMs of the television broadcast are discriminated at thetime of reproduction, and the CMs are cut off, reproduced for quickseeing, or fast forwarded at the time of reproduction. The operation ofthe second example will be described with reference to FIGS. 17, 18 and19. In this example, it is not necessary to always store the CM historyinformation in the recording medium such as the CM history memory andHDD unit.

FIG. 18 is an imaging diagram of the second example. The compressed AVdigital signal containing CMs is transferred from the VTR to the HDDunit, thereby buffered. During this interval (effective usableperiod-a), the compressed AV digital signal is expanded through anotherpath not shown, and the CM discrimination is performed by use of theexpanded signal. By referring to the CM history information obtainedhere when the data expansion output-a is produced from the HDD unit, orwhen the expanded AV digital signal is fed to the outside, it ispossible that the CMs can be cut off, reproduced for quick seeing, orfast forwarded. Repetition of the above operation (data expanded output-b) will enable long time reproduction.

The operation of this structure which is shown in FIG. 17 will bedescribed below. In FIG. 17, like function blocks corresponding to thosein FIG. 1 are identified by the same reference numerals and will not bedescribed.

While the program recorded on the magnetic tape is being reproduced, theHDD unit 52 buffers the data from the tape, and makes parallel operationof recording and reproduction. The digital AV signal reproduced from theHDD unit 52 by buffering is supplied through the digital reproductionprocessor 56 to the switching circuit 59. The switching circuit 59 isoperated to change to the contact HDD position, allowing the digital AVsignal to be fed to the data expander 71. The data expander 71 expandsthe digital AV signal, and supplies it to a video/audio separator 206.The video/audio separator 26 separates the digital AV signal into adigital video signal and a digital audio signal, which are then suppliedto video and audio output processors 210 and 207, respectively. Thevideo and audio output processors 210 and 207 restore the input signalsinto the original video and audio signals, which are then supplied to aCM predictor 208. The CM predictor 208 and a time manager 209 operate inthe same way as in the first example to predict the CM start and endpoints.

The digital AV signal produced from the data expander 71 is alsosupplied again to the digital recording processor 55, and stored in theHDD unit 52.

The expanded digital AV signal is always recorded for a predeterminedtime, for example, at least 60 seconds or more in real time in order forthe CMs to be discriminated from the program.

The digital AV signal fed to the video/audio separator 206 is alwaysread faster than the digital AV signal fed to a video/audio separator203 shown in FIG. 17. This operation is made for previously predictingthe CMs at the time of reproduction. The digital AV signal is read, forexample, at least 60 seconds or more in real time faster. In thisreading-faster operation, the CM predictor 208 detects the CM start andend points, and the detected signal is supplied to the controller, ormicrocomputer 91. The controller 91 controls the HDD unit 52 to jumpover the CMs or reproduce the CMs fast when reproducing the expandeddigital AV signal on the basis of the received detected signal. Theexpanded digital AV signal produced from the digital reproductionprocessor 56 is supplied to the video/audio separator 203. Thevideo/audio separator 203 separates it into a digital video signal and adigital audio signal, and supplies them to the video and audio outputprocessors 210 and 207, respectively. The video and audio outputprocessors 210 and 207 restore those input signals into the originalvideo and audio signals, and supply them to video and audio outputterminals 76, 75, respectively.

FIG. 19 is a block diagram of the construction of an example forreproducing the compressed digital AV signal with the CMs removed. Thereproduced compressed digital AV signal is expanded by a data expander71-b. The CM prediction is made on the basis of this expanded data inthe same way as above. The compressed digital data has a time stampsignal added to recognize time at every frame. In this example, a timebase manager 250 expands the compressed digital data in accordance withthe time stamp signal of the compressed digital data recorded in the HDDunit 52. The CMs are predicted by the CM predictor 208. Thus, thecompressed digital data and the time base after expansion can be treatedin the same dimension, and thus the CM information adapted to the timestamp signal can be supplied to the controller 91. Therefore, the HDDunit 52 having the compressed digital data recorded can be controlled toreproduce with the CMs of the buffered compressed data cut off by fastrecognizing only the time stamp information. This means that the CMpositions can be specified by reading the time code of the compresseddata. The compressed digital data reproduced by the above operation hasno CMs as a result of cutting off. It is then expanded by the dataexpander 71-b, and supplied through the external video/audio separator203 to the output terminals. In this case, since the data buffered bythe HDD unit 52 is the compressed digital AV data, there is theadvantage that the load on the HDD unit 52 is reduced.

In the second example, since the CMs are discriminated from the programat the time of reproduction, the CMs can be cut off, reproduced forquick seeing and fast forwarded from the recording media in which anyCMs are not discriminated from the program or from recording media inwhich programs were recorded by other recorder/reproducer.

A third example using the above CM discrimination method will bedescribed with reference to FIG. 14. The third example does not need thememory for always storing only the CM history information, such as theCM history memory as the second example does not, but it is differentfrom the second example in that the CMs are discriminated from theprogram at the time of recording the program.

The operation of this example will be described with reference to FIG.14. In FIG. 14, like function blocks corresponding to those in FIG. 1are identified by the same reference numerals, and will not bedescribed.

At the time of recording, the recorder/reproducer shown in FIG. 14 makesthe parallel operations of supplying the digital AV signal from the datacompressor 36 through the digital recording processor 55 to the HDD unit52 where it is buffered for a certain time, and reproducing the buffereddigital AV signal from the HDD unit 52 through the digital reproductionprocessor 56. The digital AV signal produced from the digitalreproduction processor 56 is fed through the digital recording processor53 to the VTR 51 where it is recorded on the magnetic tape. The digitalAV signal recorded on the magnetic tape is delayed by the buffering timerelative to the digital AV signal just produced from the data compressor36. The amount of buffering can be freely selected by the controller 91so that the digital AV can be delayed by an arbitrary amount.

The CM predictor 81 detects, like the previous embodiment, the switchingof video scenes, the silent pause, and the time of CM broadcast period,and supplies the predicted information of CM start and end points to thecontroller 91. The controller 91 controls the VTR 51 to record the indexsignal indicating the CM start and end points on the magnetic tapeaccording to the CM predicted information. The index signal may berecorded on the tape in the longitudinal direction or on predeterminedregions of the tape. In addition, the controller 91 may control the AVsignal with CM cut off to be recorded on the magnetic tape according tothe prediction information of CM start and end points. Also, though notshown, the position information (time stamp signal) of the compresseddigital signal may be processed by providing a time base manager as issimilar to the processing in the second example.

Moreover, while the magnetic tape is used in this example, a disk-likerecording medium, such as magnetooptical disk or phase change opticaldisk, may be used to record the prediction information of CM start andend points, instead of the magnetic tape.

In this example, the CMs are discriminated from the program at the timeof recording, and the results with the CMs removed are recorded on therecording medium. The start and end points of the CM are marked on therecording medium. Thus, the recorder/reproducer has no need to provide amemory in which the CM history information is always stored. Moreover,the CM information discriminated from the program in thisrecorder/reproducer can be used for other recorder/reproducer. In thefirst and second examples mentioned above, too, the CM historyinformation can be recorded on the recording medium after the programrecording or at the time of reproduction.

While the CMs are cut off, reproduced for quick seeing or fast forwardedin this embodiment, other portions than the CMs can be cut off,reproduced for quick seeing, and fast forwarded in this embodiment.

Thus, according to the second embodiment, at the time of recording orreproduction, the program itself of a television broadcast and the CMsinterposed in the program can be discriminated, and the CMs can beremoved (cut off, reproduced for quick seeing, or fast forwarded).

Third Embodiment

While the CMs are cut off, reproduced for quick seeing or fast forwardedat the time of receiving an analog broadcast signal in therecording/reproducing method of the second embodiment, the CMs can becut off, reproduced for quick seeing or fast forwarded at the time ofreceiving a digital broadcast signal sent as digital compressed dataaccording to the following embodiment. In the third embodiment, likeelements corresponding to those in the second embodiment are identifiedby the same reference numerals, and will not be described in detail.

FIG. 15 shows a first example of this embodiment in which the predictioninformation of CM start and end points included in a digital broadcastsignal is stored in the CM history memory at the time of recording, andthe CMs are cut off, reproduced for quick seeing or fast forwarded atthe time of reproduction.

In FIG. 15, like function blocks corresponding to those in FIG. 1 willnot be described. A digital AV signal including a digital video signal,digital audio signal and information signal is selectively received byan antenna 200 and digital receiver 201 for receiving digital televisionbroadcasts. A buffer 202, while buffering a predetermined amount of thedigital AV signal, supplies the digital AV signal. The buffer stores thedigital AV signal while the switching circuit 57 is in the contact Fposition.

The digital AV signal supplied from the buffer 202 is expanded by thedata expander 71, and then separated into the digital video signal andthe digital audio signal by the video/audio separator 206. The digitalvideo signal is fed to the video output processor 210 where the variablepoints of the video signal are detected, and the detected results aresupplied to the CM predictor 208. The digital audio signal is fed to theaudio output processor 207 where silent pauses of a certain duration aredetected, and the detected results are supplied to the CM predictor 208.The time manager 209 supplies to the CM predictor 208 time informationfor the measurement of reference time of CM. The CM predictor 208predicts the CM start and end points, and supplies them to the CMhistory memory 83 where they are stored. The reproduction method usingthe CM history memory is the same as in the first example of the secondembodiment, and hence will not be described here.

According to the first example of the third embodiment, the CMs of thedigital broadcast signal can be cut off, reproduced for quick seeing orfast forwarded on the basis of the CMs predicted information previouslystored in the CM history memory 83 at the time of recording, andtherefore the user can view the program sections continuously so thatthe usability is excellent.

The second example of the recorder/reproducer using the CMdiscrimination method will be described below. In the second example ofthe recorder/reproducer, at the time of reproduction, the CMs arepredicted in real time from the signal that is reproduced from therecording medium on which a digital broadcast was recorded, and cut off,reproduced for quick seeing or fast forwarded. The second example is thesame as in the imaging diagram of FIG. 18 in the second embodiment. Theoperation of this example will be described with reference to FIG. 10.In FIG. 10, like function blocks corresponding to those in FIG. 1 areidentified by the same reference numerals and will not be described.

Referring to FIG. 10, the switching circuit 59 is in the Tape-sideposition, and the digital AV signal is reproduced by the VTR 51 and fedthrough the switching circuit 59 to the data expander 71. The expandeddigital AV signal from the data expander 71 is supplied through thedigital recording processor 55 to the HDD unit 52 where it is bufferedfor a predetermined period of time. The expanded digital AV signal isalso predicted in its CMs by the CM predictor 208 in the same way as inthe first example, and the CM predicted information is supplied to thecontroller 91. The controller 91 controls the HDD unit 52 to reproducethe buffered digital AV signal in accordance with the CM predictedinformation, so that the CMs can be cut off, reproduced for quick seeingor fast forwarded. In addition, the CMs of compressed digital signalitself can be cut off from that signal in the same way as in the secondexample of the second embodiment.

According to the second example of the third embodiment, when therecording medium having a digital broadcast signal recorded isreproduced, the CMs can be predicted in real time, and cut off,reproduced for quick seeing or fast forwarded. Thus, since the user canview the program sections continuously, the usability is excellent.

A third example using the CM prediction method will be described withreference to FIG. 16. The third example does not need a memory foralways storing only the CM history information, such as the CM historymemory, like the second example, but it is different from the secondexample in that the CMs are discriminated from the program at the timeof recording the program.

The operation of this example will be described with reference to FIG.16. In FIG. 16, like function blocks corresponding to those in FIG. 1are identified by the same reference numerals, and will not bedescribed.

The digital AV signal including the digital video signal, digital audiosignal and information signal is selectively received by the antenna 200and digital receiver 201 for receiving digital television broadcasts.The buffer 202, while buffering a predetermined amount of the digital AVsignal, supplies the digital AV signal. The buffer continues to storethe digital AV signal for the period in which the switching circuit 57is in the contact F position.

The digital AV signal supplied from the buffer 202 is expanded by thedata expander 71, and then separated into digital video and audiosignals by the video/audio separator 206. The digital video signal issupplied to the video output processor 210 where the variable points ofthe video signal are detected, and then the detected results are fed tothe CM predictor 208. The digital audio signal is fed to the audiooutput processor 207 where silent pauses of a predetermined time aredetected, and the detected results are supplied to the CM predictor 208.The time manager 209 supplies time information for measuring referencetime of CM to the CM predictor 208. The CM predictor 208 predicts the CMstart and end points, and supplies the CM predicted information to thecontroller 91.

The controller 91 controls the VTR 51 to record on the magnetic tape theindex signal indicating the CM start and end points. The index signalmay be recorded on the tape in the longitudinal direction or on certainregions of the tape. In addition, the signal with the CMs cut offaccording to the CM predicted information can be recorded on themagnetic tape.

Moreover, while the magnetic tape is used in this embodiment, adisk-like recording medium such as magnetooptical disk or phase changeoptical disk may be used to record thereon the prediction information ofCM start and end points at the time of recording.

Thus, according to the third embodiment of the invention, since theprogram itself of a digital television broadcast and the CM sectionsinterposed in the program are discriminated, and cut off, reproduced forquick seeing or fast forwarded at the time of recording or reproduction,the effect is great.

As described above, in the reproduction method according to the thirdembodiment, the CMs can be removed (cut off, reproduced for quick seeingor fast forwarded) even at the time of receiving the digital broadcasts.

Fourth Embodiment

While in the second and third embodiments the CM discrimination meansmakes CM discrimination on the digital AV signal before beingcompressed, or on the compressed digital AV signal after expansion andconversion into the original video and audio signals, the CMdiscrimination on the compressed video and audio data before expansioncan be performed in the following embodiment. This embodiment will bedescribed with reference to FIG. 13.

In FIG. 13, like function blocks corresponding to those in FIG. 1 orFIG. 10 are identified by the same reference numerals, and will not bedescribed.

Referring to FIG. 13, there are shown a digital video change detector220 and a digital silent pause detector 221. The switching circuit 59 isin the contact HDD side position, and the digital AV signal isreproduced from the HDD unit 52 through the digital reproductionprocessor 56. The reproduced signal is separated into video and audiocompressed digital signals by the video/audio separator 206. The videocompressed digital signal includes scene change information when thevideo signal is compressed. When the scene change signal is apredetermined value or above, the corresponding frame is decided to be avideo variable point, and the decided result is supplied to the CMpredictor 81. The audio compressed digital signal is supplied to thesilent pause detector 221 where the silent pauses are decided. Since thesilent pause duration data of the audio digital signal can be compressedat a high rate, the silent periods of the audio compressed digitalsignal are discriminated from the other portions by considering that theamount of data compressed relative to real time is little. The above CMdiscrimination is made on the digital compressed AV signal read apredetermined time before it is supplied to the data expander 71 in thesame way as in the previous embodiments.

The HDD unit 52 skips over the detected CM start and end points of thedigital AV signal as described below. The digital AV signal iscompressed for every certain period of the video signal, and thiscertain period is, for example, called GOP in the MPEG compressionsystem. Therefore, by catching the digital AV data of GOPs from thecompressed digital AV signal and using the real time data obtained fromthe GOPs, it is possible that the CM start and end points are cut off orreproduced for quick seeing.

The digital AV signal produced from the digital reproduction processor56 is supplied to the video/audio separator 203 where it is separatedinto the digital video and audio signals. These video and audio digitalsignals are supplied to the video output processor 205 and audio outputprocessor 204, respectively. The video output processor 205 and audiooutput processor 204 restore those signals into the original analogvideo and audio signals and supply them to the video and audio outputterminals 76, 75, respectively.

As described above, the above operations are performed when the digitalbroadcast signal is received, and the CMs are discriminated from theprogram at the time of reproduction. Even in any one of the second andthird embodiments, the CMs discrimination can be made on the videocompressed data and audio compressed data as described above.

Thus, according to the fourth embodiment, the discrimination of CM startand end points from the program can be made on the digital AV signal atthe time of reproduction. Since the CMs can be cut off or reproduced forquick seeing in real time reproduction by directly reading the digitalAV signal and skipping over the CMs, the effect is great. In addition,since the compressed data is treated as it is, the load on the HDD unitcan be reduced.

Fifth Embodiment

The construction and operation of the digital recorder/reproducer 1according to the fifth embodiment of the invention will be describedwith reference to FIG. 7. FIG. 7 is a block diagram of the constructionof the digital recorder/reproducer according to this embodiment. In FIG.7, the expansion/reproduction processing means 7 is not shown, and likeelements corresponding to those in the first embodiment are identifiedby the same reference numerals, and will not be described in detail.

In the recorder/reproducer according to this embodiment, while abroadcast program is being recorded or timer-recorded under a timercontrol, and even if the broadcasting time of this program is extendedbeyond schedule, another broadcasting program of which the broadcastingtime overlaps this program can be recorded or timer-recorded.

For this purpose, the construction is designed to additionally have aplurality of digital processors 3′ with the analog receiver 31 of thereception/compression processor 3 left single, an extension recordingsetter 94 and a timer-recording controller 95.

The analog receiver 31 is able to receive a plurality of televisionbroadcasts at a time, and supply the video and audio signals of eachselected broadcast to the first digital processor 3′-1, second digitalprocessor 3′-2.

Here, the digital processor 3′ has the VBI decoder 32, the video ADC 33,the audio ADC 34, the video decoder 35 and the data compressor 36. Thedigital recorder/reproducer of this embodiment has a plurality of thedigital processors (the first processor and second processor).

The digital compressed data of which the time base is compressed by thefirst and second digital processors 3′-1, 3′-2 are supplied to aswitching circuit 61.

The operation of the digital recorder/reproducer of this embodiment willbe described below.

Here, under the conditions that the recording of a program 1 from 9:00p.m. to 9:54 p.m. is set on timer (timer-recording setting 1), and thatthe recording of a program 2 from 10:00 p.m. to 10:30 p.m. is set ontimer (timer-recording setting 2), it is assumed that the program 1 issuddenly changed to extend 20 minutes long in its broadcasting time.

In addition to the above case, this embodiment can also handle the casein which any one or both of the programs are shifted in broadcastingtime.

The user enters the timer-recording settings 1 and 2 through theoperation panel 93. These timer setting information are supplied to thecontroller/microcomputer 91.

When the time of 9:00 p.m. comes, the switching circuit 61 is operatedto change to the contact D1 position, allowing the compressed digitaldata (program 1) to be supplied from the digital processor 3′-1 to thedigital recording processor 53, and the digital VTR 51 starts to recordthe program 1.

Two methods of making the setting for the time extension of the program1 will be described below.

In the first method, the user enters the extension time of the program1, thereby making it possible that the VTR 51 can continue the recordingof program 1 up to the total time of the extension time and thepreviously entered end time of program 1.

The user enters the extension time or extended end time of program 1through the extension recording setter 94. The extension time settinginformation is supplied to the timer-recording controller 95 so that thecontroller 91 controls the digital VTR 51 to continue the recording upto the extended end time.

In the second method, the extension time information or extended endtime information of program 1 interfolded in the information signal istransmitted from the broadcast station to the digitalrecorder/reproducer, thus making the extended recording.

The information signal is decoded by the VBI decoder 32, and theextension time information or extended end time information of program 1of the information signal is supplied to the timer-recording controller95. The controller 91 controls the digital VTR 51 to record up to theextended end time on the basis of this extended end time information.

When the start time (10:00 p.m.) of program 2 comes under the conditionthat the program-1 extended recording operation is being executed, theswitching circuit 62 is operated to change to the contact D2 position,allowing the compressed digital data (program 2) to be supplied from thedigital processor 3′-2 to the digital recording processor 55, and theHDD unit 52 starts recording the program 2.

The recording of program 2 in the HDD unit 52 continues until theprogram 1 ends or until the program 2 ends.

When the recording of program 1 ends, the switching circuit 61 isoperated to change to the HDD side position, allowing the VTR 51 to takea copy of the program 2 from the HDD unit 52. The compressed digitaldata of program 2 is reproduced from the HDD unit 52, and transferredthrough the digital reproduction processor means 56, switching circuit61 and digital recording processor 53 to the digital VTR 51.

The controller 91 controls the switching circuits 61, 62, digital VTR 51and HDD unit 52.

Thus, according to this embodiment, while a program is being recorded ortimer-recorded, and even if this program is extended over schedule,another program of which the broadcasting time overlaps that of thisprogram can be recorded or timer-recorded completely.

A modification of the fifth embodiment will be mentioned.

While one of a plurality of timer-set programs is suddenly extended inits broadcasting time in the fifth embodiment, the digitalrecorder/reproducer of this embodiment can be operated in a mannersimilar to the first embodiment by use of the fact that the data rate ofdigital VTR is larger than that of the data compressor, therebyrecording a plurality of programs at a time on the same recording medium(magnetic tape).

This recording operation will be described with reference to FIG. 8.

First, the recording start positions of a plurality of programs(programs 1 and 2) are previously fixed on a recording medium, theprogram 1 fed from the first digital processor 3′-1 is recorded on afirst recording region A of the HDD unit 52, and the program 2 fed fromthe second digital processor 3′-2 recorded on a second recording regionB of the HDD unit 52.

After the recording start position of program 1 is fixed, a certainamount of data (1-A) of program 1 accumulated in the first recordingregion A of HDD unit 52 is first transferred to and recorded in thedigital VTR 51. In this case, since the time necessary to fix the startposition is 90 seconds, and since the total amount of data transferredduring the time taken to record is at most 75 Mbytes, the transfer timeof 60 seconds will be enough.

During this time, data of program 1 (following 1-A) is continued toaccumulate in the first recording region A, and similarly data of secondprogram 2 is continued to accumulate in the second recording region B.

Then, after the recording position of program 2 is fixed, apredetermined amount of data (2-A) of program 2 accumulated in thesecond recording region B of HDD unit 52 is transferred to and recordedin the digital VTR 51. In this case, since the time necessary to fix thestart position is 90 seconds, and since the total amount of datatransferred during the time taken to record is at most 180 Mbytes, thetransfer time of 120 seconds will be enough.

During this time, data of program 1 is continued to accumulate in thefirst recording region A, and similarly data of program 2 (following2-A) is continued to accumulate in the second recording region B.

Moreover, after the recording position of program 1 is fixed at the lastposition of the previous recording, a certain amount of data (1-B) ofprogram 1 accumulated in the first recording region A of HDD unit 52 istransferred to and recorded in the digital VTR 51. In this case, sincethe time necessary to fix the start position is 90 seconds, and sincethe total amount of data transferred during the time taken to record isat most 210 Mbytes, the transfer time of 120 seconds will be enough.

During this time, data of program 1 is continued to accumulate in thefirst recording region A, and similarly data of program 2 is continuedto accumulate in the second recording region B.

Then, after the recording position of program 2 is fixed at the lastposition of the previous recording, a certain amount of data (2-B) ofprogram 2 accumulated in the second recording region B of HDD unit 52 istransferred to and recorded in the digital VTR 51. In this case, sincethe time necessary to fix the recording position is 90 seconds, andsince the total amount of data transferred during the time taken torecord is at most 240 Mbytes, the transfer time of 180 seconds will beenough.

During this time, data of program 1 is continued to accumulate in thefirst recording region A, and similarly data of program 2 is continuedto accumulate in the second recording region B.

In addition, after the recording position of program 1 is fixed at thelast position of the previous recording, a certain amount of data (1-C)of program 1 accumulated in the first recording region A of HDD unit 52is transferred to and recorded in the digital VTR 51. In this case,since the time necessary to fix the recording position is 90 seconds,and the total amount of data transferred during the time taken to recordis at most 270 Mbytes, the transfer time of 180 seconds will be enough.

During this time, data of program 1 is continued to accumulate in thefirst recording region A, and similarly data of program 2 is continuedto accumulate in the second recording region B.

After these operations are repeated, a plurality of programs can berecorded on the same recording medium at a time.

Sixth Embodiment

The digital recorder/reproducer according to the sixth embodiment of theinvention will be described with reference to FIG. 9. FIG. 9 is a blockdiagram of the construction of the digital recorder/reproducer of thisembodiment. In FIG. 9, like elements corresponding to those in the firstembodiment are identified by the same reference numerals, and will notbe described in detail.

The digital recorder/reproducer of the fourth embodiment has the featurethat when variable-rate compressed data is recorded, or when data of adata rate lower than to record in magnetic tape is recorded, a certainamount of data is recorded once in the HDD unit 52, and the data in theHDD unit 52 is copied into the magnetic tape.

First, variable rate compressed data by MPEG compression system as atypical example of video compression means will be described.

In the MPEG compression system, for example, video data is compressed toform three pieces of image information: intraframe coded information (Ipicture), interframe coded information predicted from the past (Ppicture), and interframe coded information predicted from the past andfuture (B picture). The unit of I picture, P picture and B picture eachof which has a certain number of pictures is called GOP (Group OfPicture). The I picture, P picture and B picture are generated by use ofthe following compression means:

-   -   (1) Compression of information using spatial correlation    -   (2) Compression of information using time-basis correlation    -   (3) Compression of information using code appearance probability        deviation occurring when information is coded by the above two        compression means.

In the information compression using spatial correlation, one picture isdivided into certain pixel blocks, and DCT (Discrete Cosine Transform)is made on each of the pixel blocks, thereby decomposing one pictureinto frequency components. After DCT, the coefficients of DCT aredivided by a predetermined value, and the remainder is quantized byrounding.

Although the compression rate can be raised as the divisor is increased,the high frequency components of the video information are deleted, thusleading to the reduction of picture quality.

In the information compression using time-basis correlation, since theimage information before and after the video image are almost similar,only the image change (motion vector) is employed as information so thatthe amount of video image transmission can be greatly reduced.

In the information compression using code appearance probabilitydeviation, a short code length is assigned to the above DCT coefficientsand motion vectors of high probability values, and a long code length tothe low probability values, so that the average amount of informationcan be reduced. This operation is called the variable length coding.

Therefore, since the average, maximum and minimum data rates are, forexample, 6 Mbps, 12 Mbps and 4 Mbps, respectively, the data rate ischanged adaptively to the image of the video source.

For the sake of explanation, it is assumed that the average data rate ofthe compressed digital data generated by the variable rate datacompression is 6 Mbps and that the recording/reproduction data rate ofthe digital VTR 51 is 12 Mbps.

The data compressor 36 sends the current compression rate to thecontroller 91. The controller 91, when recognizing that the compressionrate is lower than or higher than the recording/reproduction data rate(12 Mbps) of the digital VTR 51, controls the digital VTR 51 to stopfrom recording operation, and the HDD unit 52 to start recording thecompressed digital data (6 Mbps).

The HDD unit 52, when having stored a certain amount of the compresseddigital data, starts to reproduce the recorded certain amount ofcompressed digital data while the compressed digital data (6 Mbps) isstill continued to record.

The reproduced compressed digital data is supplied through the digitalreproduction processor means 56, switching circuit 63 and digitalrecording processor 53 to the digital VTR 51 where it is recorded.

When the recorded certain amount of compressed digital data iscompletely reproduced, the digital VTR 51 is stopped from recording.

The switching circuit 63 is operated to change to the contact BUF sideposition when the above intermittent recording is performed, and it isoperated to change to the contact TH side position when normal recordingis made. The controller 91 controls the switching circuit 63 to changethe positions.

While the compressed digital data is recorded at a variable data rate inthe sixth embodiment, the data rate may be a lower or higher fixed ratethan the recording/reproduction rate of the digital VTR.

By using the HDD unit 52 as data buffer so that the digital VTR 51intermittently records every certain amounts of data, it is possible toapparently change the data recording rate of the digital VTR 51, andthus to effectively use the magnetic tape.

The compression generation means and expansion generation means in thisembodiment may be based on other systems such as MPEG-1, MPEG-2 or JPEG.

While HDD is used as a disk-like recording medium as above, thedisk-like recording medium may be other recording media such asmagnetooptical disk, phase change optical disk or semiconductor memory.

While the television broadcast receiving system chiefly for receivinganalog television broadcasts has been described in this specification,the present invention can of course be used for receiving digitaltelevision broadcasts.

Moreover, the HDD unit 52 may be incorporated in a personal computerseparated from the VTR, and connected thereto through IEEE 1394 bus orthe like. Similarly, the controller may be an external apparatus such asa personal computer, separated from the VTR.

It should be understood that the above embodiments are given forexplaining the present invention and do not restrict or narrow the scopeof the invention.

The construction of each part of the invention is not limited to thosein the above embodiments, but may be of course changed in various wayswithin the technical scopes of the claims of the invention.

The second recording medium in the present invention may be a recordingmedium capable of simultaneously recording and reproducing. Therecording and reproduction that are made at a time may be performed in atime-sharing manner.

As described above, the recorder/reproducer according to the inventioncan be used together with a recording medium such as HDD when therecording medium such as magnetic tape is recorded or reproduced, thusmaking it possible to operate in parallel with other processing so thatthe usability can be improved.

Particularly when the digital recorder/reproducer is used, the recordedprogram can be reproduced while the television signal is being recordedin the digital recorder/reproducer.

Moreover, according to the invention, the beginning end of the recordedprogram on the magnetic tape can be apparently instantly brought to beready to reproduce.

Also, according to the invention, the recorded portion of a programunder recording can be reproduced from any position while the program isbeing recorded.

According to the invention, a television broadcast program and CMsinterposed between the program sections of the program are discriminatedat the time of recording or reproduction, and the CMs are removed at thetime of reproduction so that only the program itself can be viewed.

According to the invention, while a program is being recorded ortimer-recorded, and even if this program is suddenly extended over itsscheduled end time, another program of which the broadcasting timeoverlaps that of this program can be recorded or timer-recorded.

According to the invention, HDD is used as data buffer, and the digitalVTR is operated to intermittently record every certain amounts of datafed from the HDD, thereby making it possible that the data recordingrate of the digital VTR 51 can be apparently changed to effectively usethe magnetic tape.

According to the invention, even when a magnetic disk, magnetoopticaldisk, phase change optical disk or semiconductor memory is used insteadof the magnetic tape, and even when a magnetic disk, magneto-opticaldisk, phase change optical disk or semiconductor memory is used insteadof HDD, the same effect as above can be obtained.

In addition, according to the invention, a plurality of input signalscan be recorded at different regions on the same recording medium onwhich a signal is continuously recorded by a VTR.

INDUSTRIAL APPLICABILITY

The recorder/reproducer of the present invention, while recording orreproducing on a recording medium, can make other processing, and thusthe usability can be enhanced. Particularly digital signals can beprocessed.

1. A recorder/reproducer for recording and reproducing signals,comprising: a receiver which receives signals; a first recorder whichrecords the signals received by the receiver on a first recordingmedium; a first reproducer which reproduces the signals recorded on thefirst recording medium; a second recorder which records the signalsreproduced by the first reproducer on a second recording medium; adetector which detects a commercial message portion from the signalsrecorded on the second recording medium; and a second reproducer whichreproduces the signals recorded on the second recording medium whileexcluding the commercial message portion detected by the detector. 2.The recorder/reproducer according to claim 1, wherein a capacity of thesecond recording medium is larger than a capacity of the first recordingmedium and an access speed of the second recording medium is faster thanan access speed of the first recording medium.
 3. Therecorder/reproducer according to claim 1, wherein the received signalsinclude audio signals, and the detector discriminates a portion whereinan audio signal is a stereo signal as a commercial message portion. 4.The recorder/reproducer according to claim 1, wherein the detectordiscriminates a portion as a commercial message portion if intervalsbetween changing points of the received signals correspond to a certaintime interval, and occur continuously for a certain time.
 5. Therecorder/reproducer according to claim 4, wherein the received signalsinclude video signals and audio signals, and the changing point is apoint at which a video signal level drastically changes and an audiosignal level is close to zero.
 6. A recorder/reproducer for recordingand reproducing signals, comprising: a receiver which receives signals;a detector which detects a commercial message portion from the signalsreceived by the receiver; a first recorder which records the signals andCM information indicating a location of the detected commercial messageportion on a first recording medium; a first reproducer which reproducesthe signals recorded on the first recording medium; a second recorderwhich records the signals reproduced by the first reproducer on a secondrecording medium; and a second reproducer which reproduces the signalsrecorded on the second recording medium while excluding the commercialmessage portion based on the CM information.
 7. A recorder/reproducerfor recording and reproducing signals, comprising: a receiver whichreceives program data and commercial message data; a first recorderwhich records the program data and the commercial message data receivedby the receiver on a first recording medium; a first reproducer whichreproduces the program data and the commercial message data recorded onthe first recording medium; a second recorder which records the programdata and the commercial message data reproduced by the first reproduceron a second recording medium; and a second reproducer which reproducesthe program data recorded on the second recording medium while jumpingover the commercial message data.